Attachment means for ice cutter tooth on road grader blade



April 4, 1967 YRJO MAKINEN 2 Sheets-Sheet 1 FIG. 2

Filed April 30, 1964 Mxw Filed April 50, 1964 April 4, 1957 YRJO MAKINEN 3,312,504

ATTACHMENT MEANS FOR ICE CUTTER TOOTH ON ROAD GRADER BLADE I FIG. 4

NYEN R. YR MAKW Z M.

2 Sheets-Sheet 2 United States Patent Filed Apr. 30, 1964, Ser. No. 363,770 Claims priority, applic9ation Finland, May 7, 1963, 3 63 7 Claims. (Cl. 299-24) The present invention relates to attachment means for ice cutter tooth on road grader blade, and more parti-cu larly to blades having detachable and replaceable teeth.

Various attachment means of this kind became known which, however, are noted for various disadvantages which make them expensive in use. The known ice cutter tooth attachments need frequent replacement, e.g. of the tongue inserts or of the bottom plates associated therewith.

Ice cutters are known, fitted with loose teeth which are shaped at their upper ends into wedge-like or conical pegs. The latter are attached to a holder made of a longitudinal rule with slots perpendicular to the longitudinal direction, and corresponding to the pegs. Such ice cutters also have bottom plates which are fitted with elastic tongues corresponding to the pegs, the former being adjusted so as to engage into depressions or cut-outs in the pegs in order to lock the latter.

The previously known ice cutter tooth attachments have the primary disadvantage that the elastic tongues in the bottom plates lose their elasticity rather soon, and consequently will not hold the teeth in their proper position after a few replacements. This results in the tongues or the entire bottom plates having to be renewed, which is a laborious and cost-consuming operation.

It is the object of the present invention to do away with the above-mentioned and other disadvantages inherent in hitherto known attachment means of this kind for ice cutter teeth.

, It is a further object of the invention to provide a novelice cutter tooth attachment, preferably for road grader blades, which is simple and inexpensive to manufacture, easy to install and very simple to maintain.

It is another object to provide attachment means having elastic fastening means for locking the replaceable or detachable teeth in a fastening slot of a chuck or holder element.

It is yet another object to reduce the frequency with which either the tongues or the bottom plates have to be replaced in ice cutter structures of road graders.

Accroding to the main feature of the invention, the novel attachment means for ice cutter teeth having a chuck or holder of conventional design, attached to a basic blade for fastening the replaceable teeth in the cutter, comprises one or more elastic fastening means which are adapted to lock the teeth in the fastening slots provided in the holder. These fastening means are preferably arranged in the fastening shafts or shank portions of said teeth.

In one preferred embodiment of the invention, the teeth have wedge-like shank portions provided with a longitudinal slit, the maximum width of the upper slit portion being slightly larger than the width of the upper fastening slot edge. The narrowest point of the shank portion is mainly located at the same height as, or only slightly lower than, the narrowest point of the fastening slot when the tooth is driven fully in. Owing to this expedient, the tooth becomes locked in position under the effect of the resulting spring action.

In another possible embodiment of the inventive ice cutter tooth attachment, the upper end of the tooth shank is made elastic, for instance, by decreasing the thickness 3,312,504 Patented Apr. 4, 1967 of the material. Preferably the upper tooth-shank end is so shaped as to form a retainer or tongue for locking the tooth in place in the holder.

Other objects, advantages and features of the invention will be appreciated and more fully understood with reference to the following detailed description, when considered with the accompanying drawings, wherein FIG. 1 is a cross-sectional view of a preferred, first embodiment of the inventive ice cutter tooth attachment means, taken at the fastening point of a tooth, as viewed from the side;

FIG. 2 is a longitudinal section of the attachment, taken along line IIII of FIG. 1, as viewed from the front;

FIG. 3 is a horizontal section of the attachment, taken along line III-III of FIG. 1;

FIG. 4 is a cross-sectional view similar to that of FIG. 1, but of a second embodiment of the inventive ice cutter tooth attachment; and

FIG. 5 is a front elevational view of a detachable tooth in the attachment of FIG. 4.

In the various views only those parts of an attachment for an ice cutter tooth on a road grader blade or the like are illustrated which are essential for the understanding of the invention. These parts mainly relate to the fastening of the detachable teeth. The omitted parts will be self-evident to those skilled in the art.

In FIGS. 1 through 3, a first embodiment of an inventive ice cutter tooth attachment means 10 is illustrated, having a so-called basic blade 11, an intermediate plate 12 and a chuck or holder 13, fastened to each other by conventional means (eg screws, rivet joints or the like) which are not illustrated for the sake of clarity. Bolted joints or similar members may hold the interconnected plate 12 and chuck 13 to blade 11. The rear side of chuck plate 13 is provided with equidistant adjacent slots 19 positioned substantially cross-wise to the longitudinal direction. The bottom and side walls of the slots 19 are made substantially to taper upwards like wedges (see FIG. 2). I

A detachable or removable tooth 14 is inserted in each slot 19. Each tooth 14 is formed with a wedge-shaped shank portion 15, the lower end of which is shaped to correspond to that of the fastening slots 19 of plate 13. The entire shank portion 15, or at least part thereof, is made elastic, according to the invention, with a view to preventing the tooth 14 from falling out of the respective slot 19.

In the exemplary embodiment of FIGS. 1-3, the upper portion of shank portion 15 has therein a slit 16 parallel to the longitudinal direction of the shank, the slit reaching about half-way thereof, as illustrated in FIG. 2. Owing to the provision of the slit 16, two elastic elements are formed in the upper part of the tooth shank portion 15, i.e., elastic fork limbs 17. The upper ends 18 of the elastic elements are so shaped that the distance between their outer edges is slightly larger than the width of the upper edge of the fastening slot 19.

Also, the narrowest portion of the shank 15 is located substantially at the same height as, or just slightly lower than, the narrowest point of slot 19 in chuck plate 13. When a tooth 14 is fully hammered in, it looks into position on account of the resilience of the elastic fork limbs 17.

When the ice cutter tooth attachment 10 is used for grading, teeth 14 necessarily becomes still firmer in their respective slots 19 due to the power components thus produced.

A second embodiment of the inventive ice cutter tooth attachment, generally designated 20, is shown in FIGS. 4 and 5, in views similar to FIGS. 1 and 2, respectively, of the first embodiment. Blade 21, plate 22 and holder r plate 23 are substantially identical with their respecve counterparts 11, 12 and 13 described hereinabove. late 23 has slots 29 therein for teeth 24 which have structure different from that of teeth 14. A shank ortion is shown at 25 while the upper part thereof is haped as a forwardly bent tongue 27. The front edge f this retainer tongue abuts against the top edge of the ottom of slot 29 when the tooth 24 is fully hammered in.

FIG. 4 shows how the tooth 24 is locked in position etween the interconnected plates 22, 23. The forward end of tongue 27 effectively contributes to removing the ooth upon delivering a blow, for instance with a hammer, n the direction of arrow A (FIG. 4). Other details of he ice cutter. attachment means 20 will be self-explanatory mm the illustrations.

A chuck plate or holder 13, 23 according to the invenion, as shown for cutter attachments 1i) and 20, respecively, can be made as a die forging in parts of suitable engths, and comprising a number of tooth slots. The letachable teeth, either 14 or 24, can also be made as lie forgings, fully completed without any subsequent nachining operation. It will be understood by those killed in the art that low-cost and fully interchangeable :lements can be made for the ice cutter, e.g. on a road grader, without the hitherto known high costs.

The foregoing disclosure relates only to preferred em- )odiments of the invention which is intended to include ill changes and modifications of the examples described within the scope of the invention as set forth in the appended claims. In particular, the invention contemplates the provision of other elastic "locking means provided .in the shaft or shank of a tooth for an ice cutter, substantially as explained hereinabove.

What I claim is:

1. In an attachment for ice cutter teeth on road grader olades, having basic plate means as well as chuck means and intermediate plate means attached thereto, said chuck means having therein at least two spaced-apart slots, and a removable cutting tooth in each of said slots, the improvement comprising a wedge-shaped shank portion on each tooth, wall portions of said chuck means defining the respective slots, each slot having a first section narrowing in width inwardly, in substantial alignment and registering frictional engagement with a corresponding, inwardly narrowing part of said shank portion on the respective tooth, each slot further having a second section narrowing to a lesser degree than said first slot section, and elastic fastening means formed by part of said shank portion for immobilizing each tooth within its slot, a portion of said fastening means protruding beyond the inner edge of said slot, the area of said shank portion 4 adjoining said fastening means being spaced apart from said second slot section, so as to increase resiliency of said tooth with respect to said chuck means.

2. In an attachment for ice cutter teeth, the improvement as defined in claim 1, wherein said fastening means includes a longitudinal slit in each tooth, the narrowest section of said shank portion being located substantially at the same depth as the narrowest section of the corresponding slot when said tooth and said shank portion are driven fully into said slot, whereby each tooth is locked in position under the effect of resilient forces acting between said fastening means and said chuck means.

3. In an attachment for ice cutter teeth, the improvement as defined in claim 2, wherein said fastening means includes fork limbs flanking said longitudinal slit and having a maximum width slightly larger than the Width of said inner slot edge.

4. In an attachment for ice cutter teeth, the improvement as defined in claim 2, wherein said narrowest section of the shank portion is located slightly inwardly from said narrowest slot sect-ion when said tooth and said shank portion are driven fully into said slot.

5. In an attachment for ice cutter teeth, the improvement as defined in claim 1, wherein said fastening means includes a terminal portion having the shape of a tongue, for resiliently locking said tooth within its slot.

6. In an attachment for ice cutter teeth, the improvement as defined in claim 5, wherein the thickness of said tongue-shaped terminal portion is reduced, so as to increase elasticity between said fastening means and said chuck means.

7. In an attachment for ice cutter teeth, the improve ment as defined in claim 5, wherein said terminal portion of the fastening means protrudes beyond said inner edge of the respective slot and is curved outwardly from the tooth plane, so as to increase frictional engagement with said wall portion of the chuck means in the region of said inner slot edge, while said second slot section has substantially parallel walls.

References Cited by the Examiner UNITED STATES PATENTS 2,416,654 2/1947 Taylor 37-145 2,916,275 12/1959 Bruestle et a1. 29992 FOREIGN PATENTS 672,065 5/1952 Great Britain. 87,241 4/1956 Norway.

ERNEST R. PURSER, Primary Examiner. 

1. IN AN ATTACHMENT FOR ICE CUTTER TEETH ON ROAD GRADER BLADES, HAVING BASIC PLATE MEANS AS WELL AS CHUCK MEANS AND INTERMEDIATE PLATE MEANS ATTACHED THERETO, SAID CHUCK MEANS HAVING THEREIN AT LEAST TWO SPACED-APART SLOTS, AND A REMOVABLE CUTTING TOOTH IN EACH OF SAID SLOTS, THE IMPROVEMENT COMPRISING A WEDGE-SHAPED SHANK PORTION ON EACH TOOTH, WALL PORTIONS OF SAID CHUCK MEANS DEFINING THE RESPECTIVE SLOTS, EACH SLOT HAVING A FIRST SECTION NARROWING IN WIDTH INWARDLY, IN SUBSTANTIAL ALIGNMENT AND REGISTERING FRICTIONAL ENGAGEMENT WITH A CORRESPONDING, INWARDLY NARROWING PART OF SAID SHANK PORTION ON THE RESPECTIVE TOOTH, EACH SLOT FURTHER HAVING A SECOND SECTION NARROWING TO A LESSER DEGREE THAN SAID FIRST SLOT SECTION, AND ELASTIC FASTENING MEANS FORMED BY PART OF SAID SHANK PORTION FOR IMMOBILIZING EACH TOOTH WITHIN ITS SLOT, A 